1. Field of the Invention
The invention relates to the casting of metallic strips. More particularly, it relates to the continuous casting of a superconducting ceramic strip wholly or partially sheathed in a protective metallic shell.
2. Description of the Prior Art
The fabrication of high temperature superconducting ceramics such as YB.sub.A2 C.sub.U3 O.sub.T0 here consisting of yttrium, barium, copper and oxygen, which may also contain other materials such as strontium for the barium and another rare earth element for the yttrium, presents a number of difficulties centering around the chemical stability of the end product. For example, reheating the superconducting ceramic can cause reduction of oxygen content with consequent reduction, or even loss of, superconducting properties. Moisture also has an adverse effect on the superconducting properties of the above-described ceramic. A solution to the foregoing problem is to seal or encapsulate the superconducting ceramic by some suitable means, e.g. plastic, metal housings, etc. Such a method has the disadvantage of requiring two separate steps which lead to higher costs as well as presenting the potential problem of degradation of the superconducting properties of the ceramic due to environmental (moisture, contamination, etc.) and handling factors.